1. Field of the Invention
The invention relates to an improved system for securing a fan to a drive shaft. In particular, the system is useful for securing fans in blower/vacuum systems used for vacuuming or blowing debris, such as leaves and grass clippings, from a lawn or other ground surface.
2. Background of Related Art
Although applicable in a variety of environments, the securing system of the invention is especially useful for securing a fan to an armature shaft in a blower or blower/vacuum. Various systems are known in the art for securing a fan to a drive shaft within the blower/vacuum environment. In such environments, a fan is mounted to a drive shaft for rotation. In the vacuum configuration, spaced fan blades allow a range of debris to pass through them to an outlet and generally to a collection apparatus. In the blower configuration, a discharge tube may be connected to the outlet to discharge exhaust air.
A known system is shown in FIG. 2. A centrally aligned mounting boss includes interior bores and which receive the end of a drive shaft to form an interference fit. An additional known configuration involves providing a standard nut at the end of the armature shaft. Difficulties encountered with these and other known configurations include the awkward shape of the fan creating balancing difficulties within the mold, slipping of the armature within the interior fan bores, and loosening of the standard nut. Additionally, the use of a standard nut requires relatively costly insulation between the armature and the armature shaft in order to double insulate the touchable parts.
Plastic parts tend to creep over time and as a result of moisture and temperature variations. Accordingly, prior art systems, which involve tightening an ordinary plastic nut are often inadequate because the nut tends to loosen.